BHQ880 activity in vivo was analysed by H&E staining of the bone to highlight the amount of myeloma cells and was monitored by IL-6 murine blood levels, which are produced from BMSCs and decrease when these differentiate into osteoblasts, indicating that a higher level of IL-6 correlates with a decrease in osteoblast differentiation. Here, IL6 is linked to plasma cell myeloma.